Tunable emission and morphology control of the Cu-In-S/ZnS quantum dots with dual stabilizer via microwave-assisted aqueous synthesis

Multinary quantum dots (QDs), owing to the large degree of freedom in their structure and composition, have a wide tunability in their bandgap and show an increased indeterminacy and complexity in their optical properties. In this work, a facile microwave-assisted aqueous route using sodium citrate and thioglycolic acid (TGA) as dual stabilizer was utilized to synthesize Cu−In−S/ZnS (CIS/ZnS) core/shell QDs. The effects of the shell thickness, refluxing time, pH value, temperature, Cu/In ratio and stabilizer on the morphology and optical properties of the CIS/ZnS QDs have been systematically investigated. The results show that the morphology-controllable alloyed CIS/ZnS QDs with tunable emission from 533 nm to 666 nm and long PL lifetime can be obtained by varying the molar ratio of sodium citrate to TGA. The proposed microwave-assisted aqueous synthesis method for alloyed QDs is simple, rapid, with comparatively low reaction temperature. The as-prepared QDs with the size of 3.8 nm are promising materials for lighting and biological applications.